Page 132 - General and Inorganic Chemistry for Advanced Secondary Schools Students Book Form Five and Six
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Biology for Secondary Schools
Essential and non-essential
elements in plants
Task 6.5
From reliable sources read the
FOR ONLINE READING ONLY
information about the essential and non-
(a) (b) essential elements in plants.
Figure 6.12: Examples of corms (a)
cocoyam (b) crocus There are many chemical elements
which are known to be important for
Rhizome: A rhizome is a swollen plant growth and development. These
underground stem, which grows
horizontally on the surface or just chemical elements are divided into
below the surface. An example is two major groups, namely essential
ginger, as shown in Figure 6.13. and non-essential elements. The
essential elements are vital for plant
development and survival.
The plant cannot complete its life cycle
without them. These include nickel
(Ni), carbon (C), hydrogen (H), oxygen
Figure 6.13: Ginger (O), nitrogen (N), phosphorus (P),
calcium (Ca), iron (Fe), manganese
Exercise 6.1 (Mn), potassium (K), magnesium
1. Explain the importance of (Mg), sulphur (S), boron (B), copper
chloroplasts in plants. (Cu), zinc (Zn), molybdenum (Mo),
2. Describe the internal structure of and chlorine (Cl). The non-essential
a leaf. elements are used to stimulate growth
in plants. Examples of non-essential
3. What are the roles of underground
storage organs in plants? elements include lithium (Li), iodine
(I), sodium (Na), mercury (Hg), silver
4. Why are vascular bundles important (Ag), tin (Sn), radium (Ra), silicon
in plants? (Si), bromine (Br), and cobalt (Co).
5. Explain why it is not advisable to
sleep in a room with a potted plant. The essential elements can also be
divided into two groups, which are
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